Brake mechanism.



LT. LARKIN.

BRAKE MECHANSM.

APPLICATION HLED JULY 27| SlE.

1 46,952. f y Patented Nov. 20, 1917 2 SHEETS*SHEET lr,

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BRAKE MECHANISNI.. l APPLgcATloN FILED-JULY 27,1916. 1,246,952.

anwoon a. Laramie, or Bnnralzo, new ro 1j no @niais an; assieion rosrnsninofnnemn ooi/inaar', on serrano, new "frena, a Conroe-,errori orivnw ironie ianann .ranonanisia sessione,

To all il/'wm t may concern:

Be-itlrnown that l, Emvoon T. Lenmar? a citizen of" the Unitefl- States, residin'ganf Buialq in tl'ie county of Erie and Siate vNew Yorin have invented nen. and usefni Iinproveinerrts in' Brake Meolianisrn, o'

This invention relates to -a brake rneolia nism of that type having a brake band which surrounds a brake drum and is adapted to be contracted for holding said drumA star -tionary and to be e'spanded forallowing the drum to'freely rotate as desired. The object oi' the invention is'to provide asimplel brake mechanism of this character Whicliis more particularly adapted for use with a reverse gear, in vwhich va Acertain amount of movement of the actuating parts will cause the brakev band to operatebut Where any vfurther movement of said actuat ingV parts will'not eausea further actuation of ysaid brake band.

` It is the further objeet to provide la de' vice of tiiis character 1'which will not depend on any spring action in either the aetnating parts or the brake band itself; `Wlnohv will i impose a riotional resistance '-'upon operation, which may be readily assembled and adjusted and which maybe manufaetured at low oost.

.Inthe accom anying drawings: Figures l and) 2 are fragmentary vertical transverse sections of the improved brake mechanism taken on the correspondingly numbered lines'in Fig. 3. Fig. 3 is a fragmentary top planview of the brake meebenism with the easing omitted. Fig. a is a fragmentary horizontal longitudinal section taken on line My Fig. 2.

Similar characters of reference indicate corresponding parts throughout the several views. l

l` represents l-lie braking drain AWlliolo is journaled in any suitable manner, not shown,

lsofas to be capable of rotating around a fixed longitudinal axis.' Arranged eironinn 4erentially around said drum' is the split brake band which, when contracted, 'will -hold tbe drum stationary but which when expandedl will permit said, drum to freely rotate. Preferably the' brake band is pro-- vided adjacent to its opposing ends 3, 4 with vupper raised at facesv', 6, as illustrated in the drawings.

" iounted on the end Bof the brake band in place by apin lll "in unison. The post7 asbest shownjin' .Fxg.. 4, is provided with a diametrieal opening.'

. 16 has its bead 19`at the' rside of said spontanes, Laie-1,5 me: 4leans/aiea novizio, isis; .appiieann slee ,any a?, ieilasariai no? mais.

is an upright pivot'ipost 7 a lower reduced cylindrical part orstern 8,1an' inter-- `niediate enlarged, part 49 having a cylindrical periphery andiorniing a downwardlyaef] shoulder '10V and an upper lat-4v erally projectingaiange il forming a ,ciovvn-l t Wardly projecting external shoulder 12,7

The stern 8 projectsdownwardly'into a ver# y tieal'opening 13 in tlie end Soi' the' brake band so ,thatthelower shoulder 10 bears against the flat face 5 thereof and is iield g passing horizontally ing external through 'the stenan'd tbe brake band l ,Y

On the cylindrical intermediate part of the post is journalecl a'swivel block 15 which is rotatable horizontally about the vertical the ad] a'eent part lof axis of thispost but is confined against'ver# tical movement by engagement ofthe. 'um

vderside and 'upper side of the block with.

the face 5 of the brake band and the sboul der 12, respectively, of the post, as shown in Fig. 2.

Passing horizontally and 'transversely )through botli the swivelblock and the post is an adjusting rod or boltll, 'this block being provided on its diametrieally opposite sides with suitable roundyholes 17 equality' the diameter of the bolt so as to 'Cause the i bolt 'and block to both swing about the "post 18 4which iiares fromVA its central part toward 4' itsopp'osite ends so formed to' allow tliebolt 16 .not only to pass through saidv ipost .but also to` allow' the saine to freely swirl' liorizontally to a limited extent together vWitlithe sary `turning movement. The adjusting bolt outer end thereof and y bearing against thernlter side of the [j swivel bleek Wbilejts threaded end projects'v 'i bleek.` To prevent tli'isbolt 16 relatively to' the swivel block, is. provided which engagesthe ner part of the adjusting bolt andbea'rs' against the inner face of the swivel block.

To further insure holding th'efloek nut 2U.

and bolt 16 from' beoomingloos'e a nut look is provided which preferably comprisesa double. ended locking springl which is portions with said look nnt and the heady .secured intermediate ouits lengtbfioone-V swivel block and engages its f la the adjusting bolt.4 Preferably bothsaid nut and the head of the bolt are notched or of castellated form, as shown at 22, so that the ends of the locking spring may be engaged with these notches and reliably interlock the adjusting bolt and its lock nut. The spring 21 may be securedto the swivel block in any suitable manner, for instance by' screws 23 passing through its central part. The opposite ends of the detent spring 2l are preferably held against vertical displace ment in addition to the screws 23 by means of pairs of lugs 23a arranged og the adjacent part of theswivel block aboveand below the end portions of said detent spring, as shown in Figs. l, 3 and 4. v

The threaded end of said locking bolt screws into a cam head 'or member 24, so that, by turning said bolt, said cam member maybe moved toward or away from the post upon which it is pivoted. Said cam,

member is caused to be swung around said post from one position to anotherA by means of an actuating rod 25 secured to a fork 26 whose inner end is pivoted to the cam member. Adjacent to the brake band end t this cam member is provided with a downwardly opening cam groove 27 having a pair of inwardly-facing parallel'cam faces 28 which are inclined relatively to all radii running through them from the center of the pivot post and also a pair of inwardly`facing parallel cam faces 29, which are substantially perpendicular to all radii running lthrough them from the center of said post.

Extending upwardly from the upper flat surface 6 of the brake 'band end 4 and into vthe cam groove 27 is a stud 30 which is riveted to the band end 4 and serves as a journal for an anti-friction roller 81 whose diameter is approximately equal to the dis. tance ,between the parallel faces of the two pairs of cam-faces 28 and 29, said stud being referably provided with a suitable head 32 or retaining said roller. If the cam'mem! ber 24 is turned from the position shown in Fig. 3 to that. shown in Fig. 4, the brake' band will continue to expand so long as the roller 31 engages the left hand cam face of the pair of parallel cam faces`28, but from the moment that this roller starts to engage one of the parallel inwardlyfacing cam faces 29, there will be practically no further movement of the-brake band. lf the cam member be now moved in the opposite direction, the first part of the movement will not affect the position of the brake band but i during the latter part of this movement the brake band will be contracted until the brake drum 1s tightly gripped and held stationary. This slack mot-ion to the cam faces 29 is necessary to permit of connecting a friction clutch with the same lever which actuates the rod 25, so that power may be directed by the one main lever either through said naaaeaa of the brake band is absolutely positive, no

dependence being placed on any spring K return action.. lt is however more desirable Jf'tor have the brake band constantly tending to"open up, as is the case in ordinary prac* tice, ,so as to prevent rattling of the actu-A ating'Y parts and besides, this elastic force also avoids any tendency of the ends of the i brake band to sway longitudinally one end relatively to the other when the brake band is fully opened and the cam member is at the end of its movement as inthe position shown in Fig. a. In this position, which is the normal running position, the friction,

roller 31 cannot move longitudinally in one direction due to the transverse end or stop wall 34 and it cannot freelyA move in the other direction because it would be forced to roll up the'face of the right hand member of the vparallel cam faces 29, against the said elastic force which tends constantly to open up the brake band. To prevent vertical displacement of the cam member 24 relatively to the companion end of the brake band, a detaining spring 35 is secured by means of a stud screw 37 to the latter which Vspring' extends up and over said cam member and pressing`-downwardly upon the top flat surface of the same. To prevent longitudinal displacement of the brake band the upper end of said screw 37 also engages a transverse slot 38- Which is formed in the outer end of a guide arm 39 secured to the inner side of a stationary casing 40 which incloses the brake band and drum. Thus the end l of the brake band while free to move laterally is constrained longitudinally so to prevent all longitudinal swaying and this indirectly prevents any swaying of the other end 3 of the brake band, so that the grip and release of the brake band is always steady and smooth.

This brake mechanism is readily adjusted and cannot be accidentally thrown out of adjustment; it is strong and simple and its frictional resistance being very low, the

action is very powerful and even. Itis absovlutely mechanically positive, its action being independent of spring action,and it can be manufactured at low cost.

I claim as my invention l. A brake mechanism comprising a brake drum, a brake band engaging said drum and having opposing ends, a post secured to one of the band ends and provided with'a diametrical opening, a swivel block journaled v drum, a brake band engaging said engaging member While its head bears against one side of said block, an adjusting Abrake'mechanism on said post, a cam member provided with a cam face, an adjusting 4bolt secured to said cam member and saidv swivel block and passing through said opening, a projection arranged on the other band end and bearing against said cam face, and means for turning said cam member about said post.

2. A brake mechanism comprisin a brake rum and having opposing endsa post secured to one of the band ends andprovided with a diametrical opening and cylindrical periphery, a swivel block journaled on the periphery of said post, a cam member provided with a cam face, an adjusting bolt passing through said block and the opening of said post and, 'its threaded end with vsaid cam drum, having opposing ends, oted' to oneof said band ends and provided with -tvvo cam faces one of ,the radii of ,said cam member, a-projection against one'or the other of said cam faces, and means for turning the cam memberrela# tively to its pivot. Y

4. A brake mechanism comprisingabrake drum, a brake band engaging the drum and having opposing ends,'a cam member pivoted to one of said band ends and provlded with tvvocam faces `tially perpendicular .to radii of kSaid -cam member, the other' of which is' inclined to the radii/of said cam member, a projection nut arranged on said bolt and bearing against the other side of said block, a locking spring secured to said block and engaging both the nut and head of said bolt, a projection arranged on the other band end and bearing against said 'cam face, and means for turning said cam member about said post.

against, means, for turnmgy-the cam member relatvely tof1ts pivot-,and fstops; arranged on the cam member atl to limit the movement of 'said cam member.

@empfang a brake ELWooD rr.. LARKIN..

arranged on the other band. end and bearing" a brake band engaging the a cam memberypivu 3,07 Y which isrsub-y i stantially perpendicular to radii of saidcam member, the other of which .is inclin'edto.

one of which is substanarranged on the other band end and bearing one or ythe other vot' said'cam faces,y

theends of its cam faces L and adapted to bear fagainst jsaidprojection 

